Phase I work indicates the SonicBrush is both safe and effective. Dog studies indicate no apparent damage to soft tissue after 2 months of exposure equivalent to 20x normal brushing times. In vitro studies indicate the device can damage adhesion of oral bacteria, and produce therapeutic acoustical signals many millimeters beyond mechanical contact. An IRB approved 2 week pilot study in 10 patients showed 88% of occurrences of pathogens >60,000/probe in 4-7 mm pockets reduced in number by at least a factor of 10, as well as significant reduction in supragingival plaque. In Phase II we will thoroughly evaluate efficacy and perform additional safety studies for FDA and ADA acceptance. Safety studies will include erosion effects on hard dental surfaces and bacteremia. We will refine our bacterial adhesion model to be more quantitative. Multiple site clinical studies will evaluate supragingival plaque control, and control of periodontal disease, including improvement in attachment level and reduction of subgingival pathogenic flora. Pilot studies will evaluate control of Streptococcus mutans; and efficacy in orthodontic patients. We have confirmed that the product can be battery powered, reliable, inexpensively manufactured, and well accepted by consumers. Hence the SonicBrush should provide affordable oral disease prevention to all Americans, and thereby significantly improve the health of the nation.